The present invention relates to a low noise block converter (i.e., "LNB") for the simultaneous receipt of C/Ku-band satellite-broadcasting.
The present satellite-broadcasting is carried out using C-band and Ku-band in the U.S.A., and the conventional C-band LNB and Ku-band LNB for receiving these are composed as follows.
The C-band LNB for receipt of a C-band satellite broadcasting signal of a 500 MHZ bandwidth, from 3.7 GHZ to 4.2 GHZ, consists of a band pass wave guide(WR: 229) of 3.7-4.2 GHZ, a low noise amplifier to amplify the probing signal changing abruptly a receiving frequency, a local oscillator of 5.15 GHZ to obtain an intermediate frequency of 950-1450MHZ, a mixer, and intermediate frequency (IF) amplifiers to amplify the IF signal.
And, the Ku-band LNB for receipt of a Ku-band satellite broadcasting signal of a 500 MHZ, bandwidth, from 11.7 GHZ to 12.2 GHZ, consists of a band pass waveguide(WR: 75) of 11.7-12.2 GHZ, a low noise amplifier to amplify the probing signal, a local oscillator of 10.75 GHZ to obtain the intermediate frequency of 950-1450 MHZ, a mixer and IF amplifiers.
Thus, in the past, in order to receive the C-band and Ku-band satellite broadcasting signals, the separate LNBs which have specified frequency performances, that is, 3.7-4.2 GHZ for C-band and 11.7-12.2 GHZ for Ku-band, are required so that the charge to users is increased.